The present invention relates to a management system and a computer system management method.
A storage control apparatus creates a logical volume in a RAID (Redundant Array of Independent Disks)-based storage area. This logical volume is provided to a host computer (hereinafter, host). The amount of data used by users increases on a daily basis, so that the capacity of a volume size that is configured to meet the current situation will sooner or later become insufficient. Alternatively, configuring a volume size that is in excess of the size currently needed in anticipation of increases in data quantity results in numerous nonessential and non-urgent disk drives and increases costs.
Accordingly, technology for allocating a physical page (an actual storage area) to a logical page in a logical volume in accordance with actual use has been proposed (JP-A-2007-066259, U.S. Pat. No. 7,613,945).
Measuring the number of accesses to each logical page using a per-day average value, and switching the physical page corresponding to the logical page in accordance with the daily average value is conceivable. However, although there will be differences in accordance with the type of application program, the time period during which an application program accesses the logical volume often converges on a specific time period. For example, either the number of accesses to the logical volume will be concentrated on a specific time period in the afternoon, or the number of accesses to the logical volume will be concentrated on a specific time period in the night.
In a case where access to the logical volume is bias toward a specific time period, computing the number of accesses to the logical volume as a per-day average value will not make it possible to detect the characteristic feature of a change in the number of accesses to this logical volume. The concentration of accesses on a specific time period will not emerge for an average value of the number of accesses per day, thus remaining unknown and hidden. Therefore, it will not be possible to associate a logical page comprising the logical volume with an appropriate physical page.